The company paid me to do exactly the actions I did before the system restore, which I had to redo after the system restore, and then I had to continue debugging and fixing the issue myself. Your cost analysis is fair in some cases, but it doesn’t really apply here. It wasn’t a “undo the changes so they can get back to work” situation, it was a “fix the issue so they can continue working” situation.

Also, restoring the machine to a previous state was not a fix for my issue. I wasn’t in a position where I did not have access, nor was I in one where I couldn’t revert the changes myself (even without the system restore). This was a lazy/incompetent tech, who finished their ticket and went home for the day having done nothing but inconvenience me even more, and cause me to spend even more time on the issue.

I only wish this was the only interaction I’ve ever had with IT where they proved to be more trouble than it’s worth, but sadly that’s not the case.